When her older brother returns home from school, he finds his younger sister Asuka asleep in the living room, still wearing her school uniform. As he tries to wake her, he becomes fixated on her exposed panties, growing aroused. Unable to resist, he starts peeping, sniffing her hair, and eventually becomes so turned on that his cock naturally erects. He begins masturbating while sniffing her feet. Asuka wakes up and is shocked to discover her brother jacking off while smelling her feet. The brother stammers excuses but, realizing there's no escape, drops to his knees in dogeza, dejectedly whispering, "I'm really sorry, I'm really sorry," as he tries to leave. Watching him, Asuka says, "It's not normal to get turned on by your own sister. You must be so pent up... If you promise never to do it again, I'll help you cum just this once." The brother admits he wants to smell her feet, so he jerks off while inhaling their scent—but still can't climax. He then asks to face-ride her, but still doesn't cum. Even when Asuka gives him a handjob and blowjob while riding his face, he remains unsatisfied. Asuka says, "We're siblings, so we can't actually have sex, but I can rub against you. Just release inside me like this." She begins grinding on him, but accidentally lets his cock slip inside. "Wait... big brother... you're inside," she says, but he's too lost in ecstasy to notice. He continues thrusting and cums deep inside her. Asuka mutters, "You idiot, big brother."